Circuit breaker handle assembly



June 16, 1964 D. B. POWELL CIRCUIT BREAKER HANDLE ASSEMBLY OriginalFiled Dec. 19, 1958 INVENTOR. David B. Powell Atforney United StatesPatent CIRCUIT BREAKER HANDLE ASSEMBLY David Barton Powell, Bristol,Conn, assignor to General Electric Company, a corporation of New YorkOriginal application Dec. 19, 1958, Ser. No. 781,7 66, now Patent No.3,046,371, dated July 24, 1962. Divided and this application Oct. 10,1960, Ser. No. 61,533

2 Claims. (Cl. 200-172) My invention relates to electric circuit breaksand particularly to electric circuit breakers of the multipole type,including movable contacts for each pole operated by an over-centerspring type operating mechanism, the whole being enclosed in a casing ofmolded insulating material.

This application is a division of copending application Serial Number781,766, filed December 19, 1958, now Patent No. 3,046,371, issued July24, 1962, and assigned to the same assignee as the present invention.

It is a general object of the present invention to provide an electriccircuit breaker of the type described which is extremely compact andwhich is usable in electric circuits of higher voltage and currentrating than prior circuit breakers of comparable size.

It is a particular object of the invention to provide an electriccircuit breaker of the type described including an operating handlewhich occupies a minimum of space within the circuit breaker casing andwhich may be readily attached to a handle support member internally ofthe circuit breaker casing in an extremely rigid and simplified manner.

In accordance with the invention in one form, an electric circuitbreaker is provided including a manually operable handle member ofmolded insulating material which is supported upon a metallic handlesupport member. The molded insulating handle has a relatively small baseportion which rests upon the metallic handle support. The handle supportincludes an oifset upwardly projecting tongue portion, and theinsulating handle member has an aperture therein receiving the tongueportion of the handle support in interlocking manner. A screw isinserted upwardly through the underside of the handle support memberinto threaded engagement with the insulating handle, thereby locking thehandle to the base. A thin flexible shield of insulating material isplaced over the molded handle portion to provide required insulation andclosure of the handle opening in the casing cover.

My invention will be more fully understood from the following detaileddescription, and its scope will be pointed out in the appended claims.

In the drawing,

FIGURE 1 is a top plan view of a multipole circuit breaker incorporatingthe invention, a portion of the casing being broken away; and,

FIGURE 2 is a side elevation view partially in section of the circuitbreaker 1.

In the drawing, the invention is shown as incorporated in a three-poleelectric circuit breaker comprising an insulating casing including aninsulating base portion and an insulating cover portion 11. The baseportion 10 has three line terminal members supported in correspondingrecesses at one end thereof, and three corresponding load terminals 33positioned in recesses at the opposite end of the base. The coverportion 11 is provided with portions projecting over the terminals ateach end of the base 10, and provided with apertures 93, for a purposeto be described.

The circuit breaker casing includes a plurality of pole chambers notshown, in line, respectively, with the line and load terminals 15 and33. Each of the pole chambers contains a pair of relatively movablecontacts 12 (only one pair shown) for making and breaking an electric"ice circuit through that particular pole. For the purpose of operatingthe relatively movable contacts between open and closed position,operating mechanism is provided, including a manually operable metallicsupport member 72 carrying a manually engageable insulating handleportion 76. The handle portion 76 projects through an aperture in thetop wall of the cover 11 and is manually engageable to operate theoperating mechanism.

The insulating handle 76 includes a stem portion 76a and a base portion76b. The base portion 76b is made relatively short, to occupy less spacewithin the circuit breaker casing, thereby making possible a morecompact structure. The base portion 76b also includes an opening 77,through which an offset tongue or lug 78 of the support member 72extends. An anchoring screw 79 extends through the bight portion of thehandle support member 72 upwardly into threaded engagement with thehandle member 76. It will be observed that the handle member 76 isthereby rigidly and fixedly supported on the handle supporting member 72by the use of only a single screw. In order to close the handle opening11a of the cover 11, without requiring the use of much space internallyof the enclosure, a relatively thin shield 72a is provided, which fitsover the stem 76:: and is loosely trapped between the cover 11 and thebase 76b of the molded handle. The shield 72a serves to close theopening 11a in the cover 11 in all positions of the handle.

The circuit breaker operating mechanism may be of any suitable type,such for example, as that disclosed in the above mentioned copendingapplication.

As previously mentioned, the end portions of the cover 11 are providedwith apertures 93 corresponding in location to the line and loadterminal member 15 and 33, respectively. These apertures provide accessto the clamping screws of the respective terminal members by suitablemeans such as by a screwdriver.

For the purpose of providing a simple, secure and effective closure ofthe openings, 93, lip portions 95 are provided at each of two opposedsides of the apertures in 93, and projections 96, extending inwardlyfrom the other two opposed sides of the aperture. The top surface of theprojections 96 are substantially on a line with the bottom surfaces ofthe lips or projections 95. A closure member 97, conforming generally inoutline to apertures 93 and of relatively thin resilient insulatingmaterial, is then snapped into position in each of the apertures 93 soas to assume the trapped position shown in FIGURE 2. It has been foundthat these closure members are securely retained by this constructionand that it is virtually impossible to remove them from the top surfaceof the breaker.

It will be observed that by means of this casing and handleconstruction, I have provided a circuit interrupter which is small inover-all size, inexpensive to construct and assemble, yet suitable foruse at relatively high voltages.

While I have shown only one specific form of the invention, it will bereadily appreciated that many modifications thereof may be made by thoseskilled in the art, and I therefore intend by the appended claims tocover all such modifications as fall within the true spirit and scope ofthe invention.

What I claim as new and desire to secure to Letters Patent of the UnitedStates is:

1. An electric circuit breaker comprising a molded insulating casing, atleast one relatively stationary contact mounted in said insulatingcasing, at least one movable contact movable between open and closedcircuit positions into and out of engagement with said stationarycontact, manually operable means for moving said movable contact betweensaid open and closed circuit positions comprising a handle supportingmember having a generally planar metallic portion including an olfsettongue portion, and an insulating handle member attached to said handlesupporting portion, said insulating handle member having an aperturetherein through which said tongue portion of said handle support memberprojects so that a portion thereof overlies an upper surface of saidinsulating handle member, and means fixedly attaching an intermediateportion of said insulating handle member to said handle supportingmember at a point spaced from said aperture.

2. An electric circuit breaker comprising a casing of molded insulatedmaterial, at least one relatively stationary contact mounted in saidinsulating casing, at least one movable contact movble between open andclosed circuit positions into and out of engagement with said stationarycontact, manually operable means for moving said movable contact betweensaid open and closed circuit positions comprising a handle supportingmember having a relatively short generally planar metallic portionincluding an oflset tongue portion, a handle opening in said insulatingcasing, a handle member of molded insulating material including a baseportion mounted on said handle supporting member and a stem portionprojecting through said handle opening, said base portion having anaperture therein through which said tongue portion of said handlesupport member projects, a portion of said tongue overlying a portion ofthe upper surface of said insulating handle member, retaining screwpassing through said handle support member and into a threadedengagement with said insulating handle member, and a relatively thinshield of insulating material supported on said insulating handle memberand trapped between said insulating casing and said handle supportmember, said insulating shield covering said overlying portion of saidtongue and closing said handle opening in all positions of said handle.

References Cited in the file of this patent UNITED STATES PATENTS2,286,965 Johnson June 16, 1942 2,290,495 Sandin et al. July 21, 19422,626,080 Feinberg Jan. 20, 1953 2,688,995 Wagoner Sept. 14, 19542,727,966 Reichert et a1. Dec. 20, 1955 2,829,222 Dunham Apr. 1, 19582,878,347 Schmidt Mar. 17, 1959

1. AN ELECTRIC CIRCUIT BREAKER COMPRISING A MOLDED INSULATING CASING, ATLEAST ONE RELATIVELY STATIONARY CONTACT MOUNTED IN SAID INSULATINGCASING, AT LEAST ONE MOVABLE CONTACT MOVABLE BETWEEN OPEN AND CLOSEDCIRCUIT POSITION INTO AND OUT OF ENGAGEMENT WITH SAID STATIONARYCONTACT, MANUALLY OPERABLE MEANS FOR MOVING SAID MOVABLE CONTACT BETWEENSAID OPEN AND CLOSED CIRCUIT POSITIONS COMPRISING A HANDLE SUPPORTINGMEMBER HAVING A GENERALLY PLANAR METALLIC PORTION INCLUDING AN OFFSETTONGUE PORTION,